A plug-in connector part of this type comprises a housing part, at least one electrical contact element, which is arranged on the housing part, for establishing electrical contact with the mating plug-in connector part, and a temperature-monitoring device comprising at least one sensor device for detecting a rise in temperature of the at least one contact element.
A plug-in connector part of this type can be a plug or a socket. Such a plug-in connector part can, in particular, be used in a charging device for transmitting a charging current. The plug-in connector part can in particular be formed as a charging plug or charging socket for charging a motor vehicle driven by an electric motor (also referred to as an electric vehicle).
Charging plugs or charging sockets for charging electric vehicles can be designed such that large charging currents can be transmitted. Since the thermal power dissipation increases quadratically with the charging current, such charging plugs or charging sockets require temperature monitoring in order to identify whether components of the charging plug or the charging socket are overheating in good time and so that the charging current can be modified or the charging device can even be switched off if necessary.
In a charging plug known from EP 2 605 339 A1, a temperature sensor is arranged on an insulator, approximately centrally between contact elements of the contact plug. The temperature sensor can identify whether the temperature anywhere on the contact elements has risen excessively, in order to switch off the charging process if necessary.
In a charging plug known from GB 2 489 988 A, a plurality of temperature sensors are provided, which transmit temperature data via a line. Control of a charging process depends on the temperature range within which the temperatures are recorded at the temperature sensors.
U.S. Pat. No. 6,210,036 B1 discloses a plug-in connector, in which a plurality of temperature sensors are interlinked in series by means of a single-wire line. The temperature sensors are arranged on an insulator and undergo a significant change in resistance, at a predetermined temperature, which is of such a size that a control circuit connected to the line can record the change and can either adapt or, if necessary, switch off the flow of current through the charging plug.
U.S. Pat. No. 8,325,454 B2 discloses a plug, in which thermistors that are interconnected in parallel are assigned to individual contacts and, if a threshold temperature is exceeded, switch a thyristor to “conduction mode” in order to thereby switch off a flow of current through the contacts.
In charging plugs known in the art, temperature sensors are embedded in an insulator in particular. This is needed to electrically insulate the temperature sensors from the contact elements, the temperature of which may increase. However, this simultaneously has the drawback that a change in temperature of one of the contact elements is transmitted via the insulator with a time delay and is therefore perceived at the temperature sensors with a time delay. In particular in concepts which are intended to allow for rapid switching off of a load circuit in the event of a fault, such temperature sensor arrangements are therefore not always suitable.
There is a need for a temperature-monitoring device, which can have a simple and inexpensive structure and makes it possible for the temperature of the contact elements to be monitored with rapid response behavior such that countermeasures, for example rapidly switching off a charging current, can be swiftly taken. It is also desirable here for signals from such a temperature-monitoring device to be simple to evaluate so as to identify if one or more contact elements of the plug-in connector part are overheating in a cost-effective yet reliable manner.